Inspra Side Effects, and Drug Interactions - Eplerenone

Inspra Side Effects, and Drug Interactions - Eplerenone

SIDE EFFECTS

In EPHESUS, safety was evaluated in 3307 patients treated with INSPRA and 3301 placebo-treated patients. The overall incidence of adverse events reported with INSPRA (78.9%) was similar to placebo (79.5%). Adverse events occurred at a similar rate regardless of age, gender, or race. Patients discontinued treatment due to an adverse event at similar rates in either treatment group (4.4% INSPRA vs. 4.3% placebo).

Adverse events that occurred more frequently in patients treated with INSPRA than placebo were hyperkalemia (3.4% vs 2.0%) and increased creatinine (2.4% vs 1.5%). Discontinuations due to hyperkalemia or abnormal renal function were less than 1.0% in both groups. Hypokalemia occurred less frequently in patients treated with INSPRA (0.6% vs. 1.6%).

The rates of sex hormone related adverse events are shown in Table 3.

INSPRA has been evaluated for safety in 3091 patients treated for hypertension. A total of 690 patients were treated for over 6 months and 106 patients were treated for over 1 year.

In placebo-controlled studies, the overall rates of adverse events were 47% with INSPRA and 45% with placebo. Adverse events occurred at a similar rate regardless of age, gender, or race. Therapy was discontinued due to an adverse event in 3% of patients treated with INSPRA and 3% of patients given placebo. The most common reasons for discontinuation of INSPRA were headache, dizziness, angina pectoris/myocardial infarction, and increased GGT. The adverse events that were reported at a rate of at least 1% of patients and at a higher rate in patients treated with INSPRA in daily doses of 25 to 400 mg versus placebo are shown in Table 4.

Gynecomastia and abnormal vaginal bleeding were reported with INSPRA but not with placebo. The rates of these sex hormone related adverse events are shown in Table 5. The rates increased slightly with increasing duration of therapy. In females, abnormal vaginal bleeding was also reported in 0.8% of patients on antihypertensive medications (other than spironolactone) in active control arms of the studies with INSPRA.

Creatinine - Increases of more than 0.5 mg/dL were reported for 6.5% of patients administered INSPRA and for 4.9% of placebo-treated patients.

Potassium- In EPHESUS, the frequency of patients with changes in potassium (<3.5 mEq/L or >5.5 mEq/L or ³6.0 mEq/L) receiving INSPRA compared with placebo are displayed in Table 6.

Table 7 shows the rates of hyperkalemia in EPHESUS as assessed by baseline renal function (creatinine clearance).

Table 8 shows the rates of hyperkalemia in EPHESUS as assessed by two baseline characteristic s: presence/absence of proteinuria from baseline urinalysis and presence/absence of diabetes. (See PRECAUTIONS, Hyperkalemia in Patients Treated for Congestive Heart Failure .)

Potassium- In placebo-controlled fixed-dose studies, the mean increases in serum potassium were dose related and are shown in Table 9 along with the frequencies of values >5.5 mEq/L.

Patients with both type 2 diabetes and microalbuminuria are at increased risk of developing persistent hyperkalemia. In a study in such patients taking INSPRA 200 mg, the frequencies of maximum serum potassium levels >5.5 mEq/L were 33% with INSPRA given alone and 38% when INSPRA was given with enalapril.

Rates of hyperkalemia increased with decreasing renal function. In all studies serum potassium elevations >5.5 mEq/L were observed in 10.4% of patients treated with INSPRA with baseline calculated creatinine clearance <70 mL/min, 5.6% of patients with baseline creatinine clearance of 70 to 100 mL/min, and 2.6% of patients with baseline creatinine clearance of >100 mL/min. (See WARNINGS, Hyperkalemia in Patients Treated for Hypertension.)

Sodium- Serum sodium decreased in a dose-related manner. Mean decreases ranged from 0.7 mEq/L at 50 mg daily to 1.7 mEq/L at 400 mg daily. Decreases in sodium (<135 mEq/L) were reported for 2.3% of patients administered INSPRA and 0.6% of placebo-treated patients.

Triglycerides- Serum triglycerides increased in a dose-related manner. Mean increases ranged from 7.1 mg/dL at 50 mg daily to 26.6 mg/dL at 400 mg daily. Increases in triglycerides (above 252 mg/dL) were reported for 15% of patients administered INSPRA and 12% of placebo-treated patients.

Cholesterol- Serum cho lesterol increased in a dose-related manner. Mean changes ranged from a decrease of 0.4 mg/dL at 50 mg daily to an increase of 11.6 mg/dL at 400 mg daily. Increases in serum cholesterol values greater than 200 mg/dL were reported for 0.3% of patients administered INSPRA and 0% of placebo-treated patients.

Liver Function Tests - Serum alanine aminotransferase (ALT) and gamma glutamyl transpeptidase (GGT) increased in a dose-related manner. Mean increases ranged from 0.8 U/L at 50 mg daily to 4.8 U/L at 400 mg daily for ALT and 3.1 U/L at 50 mg daily to 11.3 U/L at 400 mg daily for GGT. Increases in ALT levels greater than 120 U/L (3 times upper limit of normal) were reported for 15/2259 patients administered INSPRA and 1/351 placebo-treated patients. Increases in ALT levels greater than 200 U/L (5 times upper limit of normal) were reported for 5/2259 of patients administered INSPRA and 1/351 placebo-treated patients. Increases of ALT greater than 120 U/L and bilirubin greater than 1.2 mg/dL were reported 1/2259 patients administered INSPRA and 0/351 placebo-treated patients. Hepatic failure was not reported in patients receiving INSPRA.

BUN/Creatinine - Serum creatinine increased in a dose-related manner. Mean increases ranged from 0.01 mg/dL at 50 mg daily to 0.03 mg/dL at 400 mg daily. Increases in blood urea nitrogen to greater than 30 mg/dL and serum creatinine to greater than 2 mg/dL were reported for 0.5% and 0.2%, respectively, of patients administered INSPRA and 0% of placebo-treated patients.

Uric Acid- Increases in uric acid to greater than 9 mg/dL were reported in 0.3% of patients administered INSPRA and 0% of placebo-treated patients.

Inhibitors of CYP3A4- Eplerenone metabolism is predominantly mediated via CYP3A4. A pharmacokinetic study evaluating the administration of a single dose of INSPRA 100 mg with ketoconazole 200 mg BID, a potent inhibitor of the CYP3A4 pathway, showed a 1.7-fold increase in C_max of eplerenone and a 5.4-fold increase in AUC of eplerenone. INSPRA should not be used with drugs described as strong inhibitors of CYP3A4 in their labeling. (See CONTRAINDICATIONS.)

Administration of eplerenone with other CYP3A4 inhibitors (e.g., erythromycin 500 mg BID, verapamil 240 mg QD, saquinavir 1200 mg TID, fluconazole 200 mg QD) resulted in increases in C_max of eplerenone ranging from 1.4- to 1.6- fold and AUC from 2.0- to 2.9- fold. (See CLINICAL PHARMACOLOGY, Pharmacokinetics, Drug-Drug Interactions and DOSAGE AND ADMINISTRATION, Hypertension.)

ACE Inhibitors and Angiotensin II Receptor Antagonists (Congestive Heart Failure Post-Myocardial Infarction)- In EPHESUS, 3020 (91%) patients receiving INSPRA 25 to 50 mg also received ACE inhibitors or angiotensin II receptor antagonists (ACEI/ARB). Rates of patients with maximum potassium levels >5.5 mEq/L were similar regardless of the use of ACEI/ARB.

ACE Inhibitors and Angiotensin II Receptor Antagonists (Hypertension)- In clinical studies of patients with hypertension, the addition of INSPRA 50 to 100 mg to ACE inhibitors and angiotensin II receptor antagonists increased mean serum potassium slightly (about 0.09-0.13 mEq/L). In a study in diabetics with microalbuminuria INSPRA 200 mg combined with the ACE inhibitor enalapril 10 mg increased the frequency of hyperkalemia (serum potassium >5.5 mEq/L) from 17% on enalapril alone to 38%. (See CONTRAINDICATIONS.)

Lithium- A drug interaction study of eplerenone with lithium has not been conducted. Lithium toxicity has been reported in patients receiving lithium concomitantly with diuretics and ACE inhibitors. Serum lithium levels should be monitored frequently if INSPRA is administered concomitantly with lithium.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)- A drug interaction study of eplerenone with an NSAID has not been conducted. The administration of other potassium-sparing antihypertensives with NSAIDs has been shown to reduce the antihypertensive effect in some patients and result in severe hyperkalemia in patients with impaired renal function. Therefore, when INSPRA and NSAIDs are used concomitantly, patients should be observed to determine whether the desired effect on blood pressure is obtained.